When the moving van arrived, I realised I had underestimated how much stuff I had. There was no way my teetering pile of possessions was going to fit into the empty vehicle before me. Then, just when I needed it, a solution bubbled up from my subconscious — Tetris. Each item of furniture became a simple geometric shape. I noticed how one bed might stack squarely on top of the other. The chest of drawers, rotated 90 degrees counterclockwise, would fit snugly in the corner under the desk. Those childhood hours spent arranging blocks on a two-inch screen had finally amounted to something useful.

I am not the first to experience what psychologists call “the Tetris effect”, where a player sees those familiar blocks intrude in their real life, hallucinated across supermarket shelves and urban skylines. This phenomenon also gave its name to a 2018 game which injects the classic formula with a synaesthetic twist. Co-produced by beloved music game creator Tetsuya Mizuguchi, Tetris Effect registers each of your movements with a musical cue, so you build its soundtrack as holographic dolphins dance around the grid. 

Even with these audiovisual innovations, the most notable thing about Tetris Effect is how little it needs to change the game’s core challenge. Tetris was created 37 years ago, has been released on more than 65 platforms, sold over 495m copies, and is the model for every casual game which dominates the app store today. What has made it so enduring?